The invention of electric lights radically changes human beings' lifestyle. If there were no electric light in our lives, all works halt in the night or bad weather conditions. Given lighting is limited, it is very possible that the way houses are built and people's lifestyle will be completely different. No human being will make progress but stay in the backward age. Compared with general bulbs, light-emitting diodes (LEDs) own the advantages of lightness, long lifetime, saving power, fast switching speed, monochrome, and high reliability. Thereby, LEDs have become an indispensable optoelectric device in our daily lives.
Currently, the manufacturing methods of LEDs are novel and advanced, and thus forward LEDs, flip-chip LEDs, and vertical LEDs are developed. No matter what type of LEDs, the shapes of the emitted light are not circular. Compared with the traditional light sources, the shapes of the emitted light of LEDs are point light sources with directivity. Given the light perviousness of the whole LED, side light emission is not limited. In addition, the distribution of the light emission of most LEDs is projecting forward. Thereby, the shape of light emission of LEDs is always the subject for development for improving the light-emitting efficiency.
There is no frame in the LED fabrication process for confining the shape of light emission on the periphery of LED chips presently. Thereby, the shapes of light emission of LED chips according to the prior art are not confined for emitting a light beam. That is to say, the light-emitting device according to the prior cannot achieve straight light projection. Nowadays, LEDs are applied to massive lighting facilities. If LEDs are used as projecting light, due to their property of point light source, the illumination range cannot be concentrated by a reflection hood. Thereby, LEDs still cannot effectively replace the traditional lighting in the applications requiring spotlight effect, such as product exhibition or light focusing applications.
Accordingly, the present invention provides a light-emitting device having circular light emission, which provides circuit light emission as well as providing spotlight-like light emission.